1. Field of the Invention
This invention relates to systems providing cushioned body support for people, and more particularly, to a system generating variable pressure point body support.
2. Background
There has long been a widely recognized need for a means of relieving the discomfort of people who have to remain seated for long periods of time. This particularly has urgency for elderly or sick people who are seated on wheelchairs because of the possible development of ulcers on their buttocks due to the pressure generated by remaining in one position.
The need has been addressed by a number of inventors and manufacturers who have produced cushions containing devices that vary the cushion support points, thus shifting the areas of pressure on a person's body. An example is U.S. Pat. No. 5,487,197 by Iskra, Jr. et al. which describes a pneumatic wheelchair cushion having ajoining pneumatic chambers that are sized and shaped for cushioning a user's coccyx, ischial tuberosities, greater trochanters and thighs. The pressure in the pneumatic chambers is controlled and varied by an included controller. Another example is U.S. Pat. No. 3,867,732 by Morrell which describes a cushion having a foam rubber body which supports a number of inflatable tubes in transverse side-by-side relation. The tubes are connected to an air supply that provides inflation air pressure, and is controlled by means to inflate and deflate alternate tubes so as to vary the points of support for a person using the seat. In this invention, the person sits directly on the tubes, with the cushion being under the tubes. There are many other inflatable cushions offered for use that include rows of tubes that are alternately inflated or pulsed. Some of these are described in U.S. Pat. Nos. 2,719,986, 3,008,465, 3,148,391 and 3,678,520.
Few of these available, patented cushion assemblies have actually been sold to the public. Among other reasons, this rejection is due to perceived lack of needed portability, lack of easy adaptibility to particular needs, and the prohibitive cost of the devices offered. The high cost of these specialized devices is a particular deterrent for elderly persons who are by far the greatest number of wheelchair users.
Other situations where a variable pressure cushioning device is needed and would be much appreciated include a seat and back support for long-haul truck drivers, a seat support for office clerical workers, and back and leg support for prone patients lying in bed. Except for long-haul truck drivers, none of the above described and available cushion devices appear to be easily adapted or suitable to alleviate the foregoing seating and support needs. The matter of high cost could also discourage their use.
A variable pressure cushioning device is also needed for supporting sick or elderly animals for the same reasons as for humans. For many pet owners, this is a serious need that has not been addressed, to our knowledge.
There is therefore a need for a system which generates variable pressure point body support, cushioning a seated or prone person, which is portable, adaptable to individual needs and is relatively low in cost. There is also a need for such a system in cushioning sick or elderly animals, particularly pets.